Conventionally, in development of pneumatic tires (simply called tires below when appropriate), a prototype sample of a designed tire is made, mounted on an automobile, and subjected to an evaluation test. Thereby, the performance of the tire, such as traction performance and abrasion resistance, is obtained. When expected tire performance cannot be obtained, a new prototype sample of a tire with a modified design is made and is subjected to an evaluation test, and this procedure is repeated.
Today, due to development in a numerical analysis method, such as a finite element method, and improvement in computing power, the tire performance can be obtained through simulation. Particularly, the performance of a tire on a pavement surface can be obtained through simulation by performing analysis on the load applied by the tire to a rigid road surface and the rolling motion of the tire.
Further, various methods are proposed for predicting tire performance on a snowy road surface through simulation (for example, Non-patent Literature 1). In addition, the traction performance of an automobile on a snowy road surface is evaluated, and a relation between a normal stress applied to snow and the shear strength of the snow is obtained. There is shown a finding that this relation can be expressed in an almost linear representation, irrespective of the difference in types of automobiles, tires, and snowy road surfaces (Non-patent Literature 2).